rsvr.net Forums Homepage
Forum Home Forum Home > RSV / RSVR / FACTORY > 'How To Guides'
  New Posts New Posts RSS Feed - Haynes Valve timing warning !!
  FAQ FAQ  Forum Search   News/Blog News/Blog  Events   Register Register  Login Login

Haynes Valve timing warning !!

 Post Reply Post Reply
Author
Message
apriliano View Drop Down
Premium Member
Premium Member


Joined: 19 Nov 2013
Status: Offline
Points: 108
Post Options Post Options   Thanks (0) Thanks(0)   Quote apriliano Quote  Post ReplyReply Direct Link To This Post Topic: Haynes Valve timing warning !!
    Posted: 04 Jun 2014 at 12:41
The tear down I did was for two reasons; valve clearances and to remove the front head and barrel to sort out a stripped plug (which involved removing the engine). This was the most involved engine work I've done myself and although I'm always trying to educate myself, I don't purport to be any kind of expert.

After re-checking the valve clearances, reassembling, servicing and refitting the engine, the bike started without too much trouble. I tested the bike for a short time. It appeared to be running on just the front cylinder initially although the rear downpipe did become reasonably warm and the revs smoothed out somewhat but it wasn't quite right. I fitted the airbox and it didn't seem to make a huge difference. There was some backfiring and some popping through the rear cylinder intake. It got late so I left it until this morning. Today was much of a repeat- the front pipe got hot quickly while the rear took some time to get pretty warm although cooler than you'd expect. The bike appears to run pretty well at high revs but when you try to drop the revs down, it appears hesitant and the backfiring and popping from the intake returns. There appears to be plenty spark and I've performed some tests on the injectors and they appear to be working fine.

What are the possibilities? I felt very confident I got the timing back to where I found it but if I haven't, how do I proceed from here? Another possibility are the intake flanges- they're looking rough but appear to be okay- I swapped them front and back and thought there was an improvement in the way it was running but it started popping the back cylinder and backfiring at idle pretty quickly making me think that there had been no change.

Timing marks as they are now

http://i685.photobucket.com/albums/vv212/ianoriordan/photo1_zps5518c991.jpg
Back to Top
apriliano View Drop Down
Premium Member
Premium Member


Joined: 19 Nov 2013
Status: Offline
Points: 108
Post Options Post Options   Thanks (0) Thanks(0)   Quote apriliano Quote  Post ReplyReply Direct Link To This Post Posted: 04 Jun 2014 at 12:42
Oh poop. Thought I was in the technical forum there...
Back to Top
Spoonz View Drop Down
Admins Group
Admins Group


Joined: 11 Feb 2008
Location: North Devon
Status: Offline
Points: 9056
Post Options Post Options   Thanks (0) Thanks(0)   Quote Spoonz Quote  Post ReplyReply Direct Link To This Post Posted: 04 Jun 2014 at 15:24

It is possible to get a cam 180 degrees out even with the cam gear marking correct and have no mechaincal signs (as in things hitting other things)

I have a hunch you have done that meaning the rear is firing on the exhaust stroke. Doesn't necessarily mean it's the rear cam that is wrong even if that is misfiring because the cam timing sensor for both cylinders is on the front. So the rear is dependant on that for correct spark timing.
Back to Top
apriliano View Drop Down
Premium Member
Premium Member


Joined: 19 Nov 2013
Status: Offline
Points: 108
Post Options Post Options   Thanks (0) Thanks(0)   Quote apriliano Quote  Post ReplyReply Direct Link To This Post Posted: 04 Jun 2014 at 19:52
I think I might be a little out of my league here :/

One thing comes to mind: if it were 180 out, wouldn't the piston be at the bottom of it's cycle? I can see the top of the piston through the plug hole so doesn't it mean that between that and the fact that I have found the stop for the cranks all mean that it must be in TDC?

Assuming I may be 180 out, can I diagnose this without trial and error? Is it sufficient to assume that since the front cylinder appears to be behaving itself that it should be safe enough to reverse the rear cylinder and see if it improves? 

Thanks Spoonz
Back to Top
Spoonz View Drop Down
Admins Group
Admins Group


Joined: 11 Feb 2008
Location: North Devon
Status: Offline
Points: 9056
Post Options Post Options   Thanks (0) Thanks(0)   Quote Spoonz Quote  Post ReplyReply Direct Link To This Post Posted: 04 Jun 2014 at 20:38

I wouldn't assume it is the rear cylinder it could be either.

I would pop both rocker covers so you can see the cams. check the cam alignment marks are correct at TDC etc. If they seem ok Set the rear cylinder at TDC on a combustion stroke. Then using the crank nut behind the flywheel access window rotate the motor anti clockwise until the front cylinder is at TDC on a combustion stroke based on the front cam positions and see how many degrees you have rotated the crank by to get to that point.

In other words how many crank rotation degrees between TDC (combustion cycle) on the front to rear cylinder do you have currently.

Depending on what that figure is we will know if the cams are right. Ideally you should be checking TDC using the alignment hole in the crank via a locking pin.

Back to Top
apriliano View Drop Down
Premium Member
Premium Member


Joined: 19 Nov 2013
Status: Offline
Points: 108
Post Options Post Options   Thanks (0) Thanks(0)   Quote apriliano Quote  Post ReplyReply Direct Link To This Post Posted: 05 Jun 2014 at 00:44
I followed all of the above and all signs point to the timing being correct. In particular, the rear cylinder timing marks appeared to be so goofy on tear-down that I took tons of pictures. I was happy to sit down and try some other positions but the more I looked at my old pics, the more I became certain that it was all back the way I found it.

What about vac hoses/ breathers etc? I have to admit I lost track of them after the rebuild and had to figure out the routing from scratch. The way I have them set now, there's a hose connecting the top of the oil tank to the casing beside the clutch slave cylinder. I have a hose from the clutch cover to a T-piece that connect to either throttle body. I have the fat hose then from the rear cam cover to the airbox. I did forget to tighten the jubilee clip for the throttle body on the RHS this evening but I know it was tightened up this afternoon before I took the TB off. My feeling is that there isn't a ton of pressure there anyway but I might just give it a quick run again tomorrow with the jubilee tightened up.
Back to Top
Spoonz View Drop Down
Admins Group
Admins Group


Joined: 11 Feb 2008
Location: North Devon
Status: Offline
Points: 9056
Post Options Post Options   Thanks (0) Thanks(0)   Quote Spoonz Quote  Post ReplyReply Direct Link To This Post Posted: 05 Jun 2014 at 09:18
Originally posted by apriliano apriliano wrote:

I followed all of the above and all signs point to the timing being correct. In particular, the rear cylinder timing marks appeared to be so goofy on tear-down that I took tons of pictures. I was happy to sit down and try some other positions but the more I looked at my old pics, the more I became certain that it was all back the way I found it.

What about vac hoses/ breathers etc? I have to admit I lost track of them after the rebuild and had to figure out the routing from scratch. The way I have them set now, there's a hose connecting the top of the oil tank to the casing beside the clutch slave cylinder. I have a hose from the clutch cover to a T-piece that connect to either throttle body. I have the fat hose then from the rear cam cover to the airbox. I did forget to tighten the jubilee clip for the throttle body on the RHS this evening but I know it was tightened up this afternoon before I took the TB off. My feeling is that there isn't a ton of pressure there anyway but I might just give it a quick run again tomorrow with the jubilee tightened up.
 
Did you check how many degrees from TDC on the inlet stroke between each cylinder ? The timing marks can still be right with a cam 180 degress out of phase.

It could be vac hoses but i doubt you would get a cold cylinder from a vac leak but you never know. Your hose connections sound right from the description.
Back to Top
apriliano View Drop Down
Premium Member
Premium Member


Joined: 19 Nov 2013
Status: Offline
Points: 108
Post Options Post Options   Thanks (0) Thanks(0)   Quote apriliano Quote  Post ReplyReply Direct Link To This Post Posted: 05 Jun 2014 at 13:16
The process I went through was this: I started at the rear cylinder, popped the cover off, rotated the engine until the lobes were pointing slightly up and away from each other. I fiddled around with the locating pin until it screwed home, locking the crank. I popped out the lower spark plug and noted that the top of the piston was at the top of it's stroke. All this to me means that it's at TDC compression stroke. 

I undid the locking pin and went back to the crank. I rotated the engine until the cam lobes of the front cylinder were pointing away from each other at a slight upward angle. I noted that I had rotated the crank ant-clockwise (viewed from the LHS) approximately 60 degrees and with hardly any fiddling, I found the indentation in the crank for locking pin. I removed a spark plug and checked the location of the piston- it was at the top of it's stroke.

Before all this, I ran the bike again. The bike is running reasonably well when revved but to my ears, just wasn't right. This time, I removed both HT leads on the rear cylinder and it made no difference to the running of the bike whatsoever. I checked that there was spark by sticking a screwdriver into the top of the plug cap and earthing it to the frame of the bike. On both leads, there appeared to be a good, strong spark. In other words, it simply appears that the rear cylinder is simply not firing at all despite a strong spark and new plugs.

I also sprayed carb cleaner all over the intake flanges and this made no difference to the running.
Back to Top
Spoonz View Drop Down
Admins Group
Admins Group


Joined: 11 Feb 2008
Location: North Devon
Status: Offline
Points: 9056
Post Options Post Options   Thanks (0) Thanks(0)   Quote Spoonz Quote  Post ReplyReply Direct Link To This Post Posted: 05 Jun 2014 at 14:02

sounds like you have found the problem.

60 degrees of crank rotation between the same stroke from one cylinder to the other. Think about that for a minute and you will see that is not right.
 
although you rotated it 60 degrees to the next TDC, that should be TDC on the exhaust stroke of the other cylinder so the cam positions should reflect that. The combustion stroke would be 360 degress further on from that which i would make 420 deg from my pants maths.
 
So 420 deg anti clockwise from rear cylinder combustion stroke to the front cylinder is on the same stroke. So in essence if your happy the rear cams are correct, rotate the crank 420 deg anti clockwise and the cams should be in the same phase on the front cylinder as they were when you looked at the rear cylinder at the start. If the cams only need 60 deg of crank rotation to reach the same position front to rear then they are out of phase.
 
Someone might want to check my maths before you take that as gospel. Ring Griff if you want a second opinion.
 
 
 
Back to Top
Guests View Drop Down
Guest Group
Guest Group
Post Options Post Options   Thanks (0) Thanks(0)   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 05 Jun 2014 at 20:42
Back to Top
apriliano View Drop Down
Premium Member
Premium Member


Joined: 19 Nov 2013
Status: Offline
Points: 108
Post Options Post Options   Thanks (0) Thanks(0)   Quote apriliano Quote  Post ReplyReply Direct Link To This Post Posted: 05 Jun 2014 at 20:55
Ya, that makes a lot of sense. To be honest, I was very suspicious about the fact that the compression stroke for both cylinders seemed to be just a split second apart but everything I read (honestly, I'm not an engine guy) made it seem that that was right. 

I'll have to admit I'm feeling pretty embarrassed at the moment.

Can I ask you then that if the front cylinder is working fine that it must mean that it's the back I need to work on to correct the problem? I presume that the back cylinder is firing on the intake stroke? Since the Haynes insists on starting with the rear cylinder, is it sufficient to rotate the rear cylinder 360 degrees from it's current position, lock it off and set the cams again?
Back to Top
Spoonz View Drop Down
Admins Group
Admins Group


Joined: 11 Feb 2008
Location: North Devon
Status: Offline
Points: 9056
Post Options Post Options   Thanks (0) Thanks(0)   Quote Spoonz Quote  Post ReplyReply Direct Link To This Post Posted: 05 Jun 2014 at 22:10
Originally posted by apriliano apriliano wrote:

Ya, that makes a lot of sense. To be honest, I was very suspicious about the fact that the compression stroke for both cylinders seemed to be just a split second apart but everything I read (honestly, I'm not an engine guy) made it seem that that was right. 

I'll have to admit I'm feeling pretty embarrassed at the moment.

Can I ask you then that if the front cylinder is working fine that it must mean that it's the back I need to work on to correct the problem? I presume that the back cylinder is firing on the intake stroke? Since the Haynes insists on starting with the rear cylinder, is it sufficient to rotate the rear cylinder 360 degrees from it's current position, lock it off and set the cams again?

Your cams sound correctly positioned in isolation to each cylinder just out of phase with each other and the trigger from the cam position sensor.

When the front cylinder is on combustion i think the rear will be on intake, if it's 360 degress out of phase crank wise the rear is currently on exhaust when the front is on combustion off the top of my head.

I would start again and at TDC on the rear cylinder make sure your cam marks are set. Then go 420  degrees counter clock where you should find it is at TDC on the front cylinder and align the cams on the front cylinder. I think you will find the cams are 180 degrees out on the front. Then rotate the motor by hand to make sure all is free etc and watch the cams to make sure after 420 degrees it's goes from the same phase on one cylinder to the same phase on the other and the cam marks still line up.

Once you are happy that is the case and it rotates freely cross your fingers and go for a startup. Be doubly sure that motor is free through a complete cycle first cos you don't want  to trash the motor if there is a mistake.

If it runs sweet then call Haynes and tell them they are twats assuming they still exist.


Back to Top
tapmyhed View Drop Down
Premium Member
Premium Member
Avatar

Joined: 11 Feb 2008
Location: Suffolk
Status: Offline
Points: 1920
Post Options Post Options   Thanks (0) Thanks(0)   Quote tapmyhed Quote  Post ReplyReply Direct Link To This Post Posted: 06 Jun 2014 at 07:38
This is a brilliant read......who knew?????
Added to my good gen book!
Factory 04
Big Bore Whore
Back to Top
apriliano View Drop Down
Premium Member
Premium Member


Joined: 19 Nov 2013
Status: Offline
Points: 108
Post Options Post Options   Thanks (0) Thanks(0)   Quote apriliano Quote  Post ReplyReply Direct Link To This Post Posted: 07 Jun 2014 at 11:43
Grateful greetings from the back of the class. Engine sorted. Purring like dream. It'll go back together today for a test run or five.


Back to Top
Wavestarved View Drop Down
Premium Member
Premium Member
Avatar

Joined: 15 Oct 2012
Location: Up sh*t creek
Status: Offline
Points: 2310
Post Options Post Options   Thanks (0) Thanks(0)   Quote Wavestarved Quote  Post ReplyReply Direct Link To This Post Posted: 09 Jun 2014 at 23:50
Spoonz, you da man! Right on the money from the start.
Life aint about the destination, life's about the journey. That's why we ride!
www.apriliaperformance.co.uk
www.apriliaforum.co.uk
www.apriliaownersclub.co.uk
Back to Top
Mikee View Drop Down
Moto2 racer
Moto2 racer


Joined: 26 May 2013
Location: Fife
Status: Offline
Points: 144
Post Options Post Options   Thanks (0) Thanks(0)   Quote Mikee Quote  Post ReplyReply Direct Link To This Post Posted: 01 Feb 2017 at 09:28
I remember reading somewhere that they only line up with the marks once every 45 revolutions of the crank
 
mike
Back to Top
 Post Reply Post Reply
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 11.10
Copyright ©2001-2017 Web Wiz Ltd.

This page was generated in 0.047 seconds.